Maybe the current meds are not working for her and she needs to change them. Also do you know for sure that she actually takes the medication or she just tells you she takes it. I have bipolar and had trouble with school and relationships at her age also and my problems got very bad requiring hospitalization after I started getting heavier into drug use at 18. You sound like probably how my mother sounded at that time. Not over the same exact problems but nonetheless not everyones symptoms of things are exactly the same but end up with the same results.